# Copyright (c) 2018 Presto Labs Pte. Ltd.
# Author: leon

import json
import logging
from typing import List, Union

from tornado import gen

import coin.flow.topic_map as topic_map
from coin.base.param_util import to_list
from coin.exchange.base.ws.subscriber import WebsocketJsonSubscriberBase


class KorbitSubscriber(WebsocketJsonSubscriberBase):
  def __init__(self,
               queue,
               group_id: str,
               worker_id: str,
               symbol: Union[List[str], str],
               close_callback=None,
               logger=None):
    super().__init__(close_callback, logger or logging.getLogger(__name__))
    self._symbol = to_list(symbol)

    self._register_url('wss://ws-korbit.pusher.com/app/2dbc1cc8b255f30f446b?protocol=7')
    self._publisher = None
    self._init_publisher(queue, group_id, worker_id)

  def _init_publisher(self, queue, group_id: str, worker_id: str):
    topic_depth = topic_map.search_topic_id('korbit_ws_depth_%s%s' % (group_id, worker_id))[0]
    topic_trade = topic_map.search_topic_id('korbit_ws_trade_%s%s' % (group_id, worker_id))[0]

    self._publisher = {
        'book': queue.get_writer(topic_id=topic_depth[1]),
        'trade': queue.get_writer(topic_id=topic_trade[1]),
    }

    self._enable_topic_event_publisher(queue, 'korbit_ws_topic_event', [topic_depth[0]])
    self._add_teardown_callback(self._teardown_publisher)

  @gen.coroutine
  def on_open(self):
    yield self._send_subscribe_request()

  @gen.coroutine
  def _send_subscribe_request(self):
    subscribe_depth_str = json.dumps({
        "event": "pusher:subscribe", "data": {
            "channel": "orderbook"
        }
    })
    yield self._ws.write_message(subscribe_depth_str)

    self._publish_topic_event('START')
    self._logger.info('Subscribe done')

  def _teardown_publisher(self):
    if self._publisher:
      for _, publisher in self._publisher.items():
        publisher.close()
      self._publisher = None

  def on_message(self, timestamp: int, message: bytes):
    if self.stopped:
      return

    event = message['event']
    if event in ('pusher_internal:subscription_succeeded', 'pusher:connection_established'):
      self._publish_topic_event(message)
    elif event.endswith('order'):
      self._publisher['book'].write(timestamp, message)
    elif event.endswith('match'):
      self._publisher['trade'].write(timestamp, message)
    else:
      self._logger.error('Unknown message: %s' % message)
